Garmin, the global leader in wearable fitness technology, is pushing the boundaries of health tracking. A newly published patent reveals that the company is working on a novel method to monitor hydration levels and hematocrit concentration using optical sensors. This breakthrough could redefine how smartwatches assess real-time health.
Optical Tech Behind the Innovation
The patent, granted in the U.S., details a system based on pulse spectroscopy. This is an advanced version of photoplethysmography (PPG), a light-based method already used in many smartwatches for heart rate and oxygen tracking.
The system uses near-infrared light wavelengths—specifically around 850 nm and 1000 nm. These wavelengths penetrate the skin and allow for a more accurate read on blood volume and tissue characteristics. Garmin’s system measures pulsatile volume changes in blood vessels compared to surrounding tissue. These variations are then analyzed to determine hydration and hematocrit levels.
What is Hematocrit?
Hematocrit means the % of RBC in the blood. It plays a critical role in oxygen delivery. Abnormal levels can signal dehydration, anemia, or overtraining. Until now, measuring hematocrit typically required invasive lab tests. Garmin’s wearable method could make this data accessible to everyday users and athletes alike.
Hydration Tracking Reimagined
Unlike current hydration reminders based on time or estimated sweat loss, Garmin’s patented method could track actual hydration changes in the body. This can be a game-changer for endurance athletes, fitness enthusiasts, and even those with medical conditions sensitive to fluid levels.
Users could receive alerts like:
“Your hydration is 4% below optimal,”
rather than generic prompts like “Time to drink water.”
Potential Applications
Endurance training: Prevent dehydration and monitor red blood cell health.
Recovery tracking: Detect overtraining early through hematocrit changes.
Health management: Monitor real-time hydration during illness or travel.
General wellness: Track water needs more scientifically than manual logging.
Timeline for Release?
While the technology is promising, a patent does not confirm an imminent release. Garmin will need to conduct clinical trials, ensure regulatory approvals, and optimize sensor calibration for various skin types. Experts suggest it could take 12–24 months before these features debut in consumer devices.
If integrated, it will likely appear first in Garmin’s premium models like the Fenix, Forerunner, or Epix lines.
Disclaimer:
This article is based on publicly available information from Garmin’s recent patent filing. The features discussed are conceptual and may not reflect final products. Garmin has not officially announced any product with this capability as of now.